On Tue, May 19, 2009 at 07:09:04PM -0700, Pawel Wojcik wrote: > On 05/19/09 06:23 PM, Edward Pilatowicz wrote: >> On Tue, May 19, 2009 at 10:37:45AM -0700, Terry Whatley wrote: >> >>> 4.3.4 disk power attribute driver properties >>> >>> sd(7D) will export a set of driver properties to indicate a disk's >>> power attributes. See Table-2. >>> >>> Table-1 Disk Power Attribute Properties (array properties are indexed >>> by power state in order of ascending power levels) >>> ------------------------------------------------------------------------ >>> Prop Name Prop Type | Prop Description >>> ------------------------------------------------------------------------ >>> "pm-resource-type" String | "resource-spindle-disk" for the >>> | spindle disks >>> ------------------------------------------------------------------------ >>> "pm-perf" Integer array | array of average R/W >>> | performance percentages >>> ------------------------------------------------------------------------ >>> "pm-pwr-saving" Integer array | array of average power saving in >>> | units of 0.1watt >>> ------------------------------------------------------------------------ >>> "pm-latency" Integer array | array of time to first data in units >>> | of 100ms >>> ------------------------------------------------------------------------ >>> >>> >> >> exporting performance statistics via device properties seems weird to >> me. is there a precedent for this? why isn't this information being >> exported via kstats? do we really want to train users to start using >> prtconf -v to get performance data? >> >> ed >> > I think these are not performance statistics. I believe that these are > static arrays that are specific for a device type (most likely Sun disks > only), that correlate specific power level with performance and power > savings. These properties, I believe, are to be used by a storage power > manager to decide at what power level disk should run at given time. > Jane Chu may correct me here... > -Pawel >
if that's the case then having them as device properties seems ok, but documentation for these properties should make it clear that these are not actual system performance numbers. ed
